Problem: Khan.scratchpad.disable(); For every level Christopher completes in his favorite game, he earns $550$ points. Christopher already has $180$ points in the game and wants to end up with at least $3060$ points before he goes to bed. What is the minimum number of complete levels that Christopher needs to complete to reach his goal?
To solve this, let's set up an expression to show how many points Christopher will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Christopher wants to have at least $3060$ points before going to bed, we can set up an inequality. Number of points $\geq 3060$ Levels completed $\times$ Points per level $+$ Starting points $\geq 3060$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 550 + 180 \geq 3060$ $ x \cdot 550 \geq 3060 - 180 $ $ x \cdot 550 \geq 2880 $ $x \geq \dfrac{2880}{550} \approx 5.24$ Since Christopher won't get points unless he completes the entire level, we round $5.24$ up to $6$ Christopher must complete at least 6 levels.